[llvm] [AMDGPU] In a tie, unpack packed instructions to avoid issue stalls (PR #165641)

[Matt Arsenault via llvm-commits]

================
@@ -1167,3 +1167,69 @@ body:             |
     $vgpr5 = V_MOV_B32_e32 killed $sgpr15, implicit $exec, implicit $exec
     renamable $vgpr16_vgpr17 = nofpexcept V_PK_MUL_F32 8, killed $sgpr30_sgpr31, 11, killed $vgpr4_vgpr5, 0, 0, 0, 0, 0, implicit $mode, implicit $exec
     S_ENDPGM 0
+...
+---
+name:            test_tie_unpack_minimal
+tracksRegLiveness: true
+
+liveins:
+  - { reg: '$vgpr0_vgpr1_vgpr2_vgpr3' }
+  - { reg: '$vgpr4_vgpr5_vgpr6_vgpr7' }
+  - { reg: '$vgpr8' }
+  - { reg: '$vgpr9' }
+  - { reg: '$vgpr10_vgpr11' }
+  - { reg: '$vgpr12_vgpr13' }
+  - { reg: '$agpr0_agpr1_agpr2_agpr3_agpr4_agpr5_agpr6_agpr7_agpr8_agpr9_agpr10_agpr11_agpr12_agpr13_agpr14_agpr15' }
----------------
arsenm wrote:

```suggestion
```

Don't actually need to record the function live ins 

https://github.com/llvm/llvm-project/pull/165641